Fakir>> Экзотическая схема в статье в JBIS - солнечный парус-дуршлаг. Статья целиком недоступна, только первая страница, так что смысл такой странной идеи остаётся совершенно непонятен (разве что перфорация размерами меньше длины волны, и типа так уменьшить массу???
Fakir> Собственно исходная задумка именно такая:
Fakir> https://apps.dtic.mil/sti/tr/pdf/ADB088771.pdf#page=107
Fakir> То есть тупиковая, фундаментально.
1983
Techniques exist in the laboratory to make a thin perforated
sail. Focused ion beams have already demonstrated the capability
to
make holes down to 0.1 microns, well below solar light
wavelengths. Crossed holographic gratings have already been
developed in photosensitive resists and used to make
arrays of
square posts with 0.2 to 0.5 micron spacing. The use of a
positive rather than a negative resist would produce a square
grating with similar sized square holes.
A schematic design of a perforated microstructured solar sail is
shown in Figure 3-1 [Forward 1983]. The basic concept is to
decrease the mass per unit area of an aluminum or aluminum coated
kapton sail by making submicron perforations in the sail
material. If the holes are significantly smaller than a
wavelength of light, the light will be reflected.
Solar sails in earth orbits will not experience high light
fluxes, so their normal infrared reradiation will suffice to keep
them from melting. If, however, high intensity laser light is
used to push the sail, or the sail is to travel in near the sun
during its mission, it will need to have an improved emissivity
on the backside to keep the sail temperature below the melting
point. The emissivity of a metal surface can be increased over
the bulk metal emissivity by constructing microstructures on the
backside that have dimensions corresponding to the peak infrared
wavelength emitted by the sail at its operational temperature.
In the example shown in Figure 3-1, the microstructures are
simple quarter-wave antennas driven at the base by random thermal
Nyquist currents. The radiation pattern from these simple spikes
is not optimum, being a doughnut shaped pattern with a null in
the rearward direction, but there should still be a significant
increase in emissivity with these structures. More complicated
microstructures such as broadband end-fire antennas or slots may
have better emissive properties although they will be more
difficult to fabricate.
IF the mass of an unfurlable plastic-backed sail can be lowered
to 0.1 metric tons per square kilometer by using perforation
techniques, then it will have the low mass and performance of an
aluminum film sail with the ruggedness and unfurlabilty of a
plastic-backed sail.
IF a perforated aluminum film sail can be made with a
10:1
reduction in mass over a non-perforated film sail, then new
missions become possible, such as creating new geostationary
orbits that are not on the equator. One such concept is
described on the next section.
POLAR LEVITATED GEOSTATIONARY ORBITS USING PERFORATED SOLAR SAILS
One of the potential applications of an ultrathin perforated
solar sail is to use the light pressure from the sun to levitate
the orbit of a geostationary satellite up out of the equatorial
plane. At the present time, the only geostationary orbits are
those along the equator at 35,800 kilometers altitude
(42,200 kilometers from the center of the earth). Although
geostationary spacecraft can be seen at the Arctic and Antarctic
Circles (depending upon the local horizon topography), they
cannot be used by ground stations near the poles.
If a spacecraft were supplied with a lightweight sail, it could
use the sunlight to supply a cot.stant force in the poleward
direction.
Чуть смягчаю своё мнение: задумка не
фундаментально тупиковая. В предложенном узконишевом применении какой-то кроооохотный шансик имела бы. Если такая ниша кому-то бы сильно понадобилась.